Only attempt go.mod updating if go >= 1.16

Prior to this (a) Go will attempt to update go.mod/sum anyhow, and (b) the `mod tidy -e` option isn't available.

extractor/cli/go-autobuilder/go-autobuilder.go

@@ -290,7 +290,8 @@ func main() {
 		}
 	}
 
-	if depMode == GoGetWithModules {
+	// Go 1.16 and later won't automatically attempt to update go.mod / go.sum during package loading, so try to update them here:
+	if depMode == GoGetWithModules && semver.Compare(getEnvGoSemVer(), "1.16") >= 0 {
 		// stat go.mod and go.sum
 		beforeGoModFileInfo, beforeGoModErr := os.Stat("go.mod")
 		if beforeGoModErr != nil {
@@ -324,7 +325,6 @@ func main() {
 					log.Println("We have run `go mod tidy -e` and it altered go.sum. You may wish to check these changes into version control. ")
 				}
 			}
-
 		}
 	}